The present invention relates generally to optical measurement and, more particularly, to a system and method for measuring the cell gap of a liquid crystal cell.
With the advent in semiconductor processes, electronic products are increasingly required to be lightweight, compact and low profile. Consequently, the fabrication of liquid crystal display (“LCD”) panels, which have been widely used in electronic products, has become more complex. An LCD panel usually comprises an upper glass substrate, a lower glass substrate and intermediate layers sandwiched between the glass layers. The intermediate layers may include a color filter layer, indium tin oxide (“ITO”) layers, alignment films and a liquid crystal cell filled with a liquid crystal. The thickness or the cell gap of the liquid crystal cell is an important factor to control because the properties such as display color, response speed and orientation stability of a liquid crystal cell depend upon the cell gap. Accordingly, in order to use a liquid crystal cell, it is important to measure the cell gap.